title: Adiabatic circular polarizer based on chiral fiber grating.
abstract: Based on the adiabatic coupling principle, a new scheme of a broadband circular polarizer formed by twisting a high-birefringence (Hi-Bi) fiber with a slowly varying twist rate is proposed. The conditions of adiabatic coupling for the adiabatic polarizer are first identified through analytical derivations. These conditions are easily realized by choosing a reasonable variation of the twist rate. Moreover, the bandwidth of the polarizer is able to be directly determined by the twist rates at the two ends. Finally, the broadband characteristics of the polarizer are demonstrated by simulations. It is also shown that the performance of the polarizer can be remarkably improved by accomplishing a multi-mode phase-matching along the grating or by using of the couplings of the core mode to lossy modes.
authors.affiliation: Department of Electronic Engineering and Information Science, University of Science and Technology of China, Hefei, Anhui 230027, China. yanglil@ustc.edu.cn
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Lin-Lin
authors.initials: LL
authors.lastname: Xue
authors.forename: Cheng
authors.initials: C
authors.lastname: Li
authors.forename: Jue
authors.initials: J
authors.lastname: Su
authors.forename: Jing-Ren
authors.initials: JR
authors.lastname: Qian
mesh_terms: D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D008962:Models, Theoretical; D012031:Refractometry / Q000295:instrumentation*